The relaxed and stretched ligaments and tendons supporting the pelvis and lumbar spine are particularly stressed during pregnancy. Excessive mobility in these areas can cause the surrounding muscles to become and stay in spasmed in order to provide support. The woman’s posture is altered as the increasing weight of the baby shifts the center of gravity forward. These factors combine to cause poor posture such as lordosis and kyphosis, both of which can cause and exacerbate back pain.
Traditionally accepted as inevitable, low back pain is the most common complaint during pregnancy (1). One study showed that 86% of women who were 36 weeks pregnant had difficulty in doing a simple sit-up (2). In the scientific literature, the most common back pain in women is in the lumbosacral region (3).
What are the risk factors for back pain/discomfort during pregnancy?
- Previous back pain (not related to pregnancy)
- Smoking
- Strenuous occupations
- Lordosis present before pregnancy
- Multiple pregnancy
- Young women
- Women of small stature
- Obesity
- Inactivity
- High level alcohol consumption
- Previous motor vehicle accident
- Previous fall
What are the causes of back pain during pregnancy?
- Weight gain
- Gravity center shift anteriorly
- Relaxin increase joint mobility, muscle become tighter to stabilized joint
Ligamentous hyperlaxity, increased weight and change of posture seem to be the three causes of back pain that almost half of all women suffer during pregnancy.
Ligamentous hyperlaxity
During pregnancy the ovaries and later the placenta secrete the hormone relaxin which, as the name suggests, prepares the body for the expansion of the volume occupied by the foetus and also for childbirth. The ligament is important for joint support and in some women the joint is at risk of trauma if there is a lack of muscle tone to balance this lack of ligament support. There will then be micro tears in the ligaments and/or muscle fatigue as the muscles are not used to or do not adapt well to this overload.
Change in posture
In the pregnant woman, the body’s centre of gravity is displaced anteriorly. This has the effect of increasing the lumbar and cervical curves forwards and the back curves backwards. The lumbar and cervical extensor muscles as well as the pectoral muscles will be shorter and contracted and therefore prone to micro-tears. On the other hand, the lumbar and cervical flexor muscles will be relaxed and loose. This lack of harmony between them will be the source of joint slippage, especially in the lumbosacral and sacroiliac region and the lumbar facet joints.
An increase in the lumbar curve will cause:
- Forward tilt of the pelvis (flexion)
- An increase in the lumbosacral angle.
- The psoas will be shorter
- The extension muscle will be shorter.
- The abdominals will be lengthened and lose their supporting strength.
Indeed, an increase in lumbar and cervical lordosis will have the effect of having lumbar and cervical extensor muscles in permanent hyper contraction. On the other hand, the flexion muscles in the cervical and lumbar regions lose a lot of their vitality. In the scientific literature, the back pain most frequently encountered in women is in the lumbosacral region (4). The myofascial knots of the psoas muscle will be responsible for the pain felt in the lower back and gluteal region. Traditionally accepted as inevitable, low back pain is the most common complaint during pregnancy (4). One study showed that 86% of women who were 36 weeks pregnant had difficulty in doing a simple sit-up (5).
In the scientific literature, the most common back pain in women is in the lumbosacral region (6). Ligamentous hyperlaxity, increased weight and change of posture seem to be the three causes of back pain that almost half of the women suffer during pregnancy. An increase in lumbar and cervical lordosis will have the effect of having lumbar and cervical extensor muscles in permanent hyper contraction. On the other hand, the flexion muscles in the cervical and lumbar regions lose a lot of their vitality.
In the scientific literature, the back pain most frequently encountered in women is in the lumbosacral region (7). The myofascial knots of the psoas muscle will be responsible for the pain felt in the lower back and gluteal region.
What are the symptoms of back pain during pregnancy?
- Lower back pain during pregnancy is usually located at and above the waist, in the center of the back, and may be associated with pain that radiates down the woman’s leg or foot.
- Posterior pelvic pain is four times more prevalent than low back pain during pregnancy. This is a sharp pain felt below the belt, on one or both sides, or in the coccyx.
Reference
- Mantle MJ, Greenwood RM, Currey HL., Rheumatol Rehabil. 1977 May;16(2):95-101. Backache in pregnancy.
- Daly JM, Frame PS, Rapoza PA. Sacroiliac subluxation: a common treatable cause of low back pain during pregnancy. Fam Pract Res
- Berg et al., 1988; Fast et al., 1987; Mens et al., 1996.
- Mantle MJ, Greenwood RM, Currey HL., Rheumatol Rehabil. 1977 May;16(2):95-101. Backache in pregnancy.
- Daly JM, Frame PS, Rapoza PA. Sacroiliac subluxation: a common treatable cause of low back pain during pregnancy. Fam Pract Res
- Berg et al., 1988; Fast et al., 1987; Mens et al., 1996.
- Berg et al., 1988; Fast et al., 1987; Mens et al., 1996.
